ios - 使用SDWebImage下载图片，错误-999(或)SDWebImageErrorDomain Code=0 "下载的图片有0像素

Question

我无法使用 SDWebImage 4.4.5 版本在 Objective c 中下载图像，我尝试了以下方法，但没有任何效果。

尝试 1:

[self.thumbnailImageView sd_setImageWithURL:[NSURL URLWithString:thumbnailURLString] completed:^(UIImage * _Nullable image, NSError * _Nullable error, SDImageCacheType cacheType, NSURL * _Nullable imageURL) {

}];

尝试 2:

[self.thumbnailImageView sd_setImageWithURL:[NSURL URLWithString:thumbnailURLString] placeholderImage:nil options:SDWebImageRefreshCached completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType, NSURL *imageURL) { if(image != nil){
            self.thumbnailImageView.image = image;                
        } else {
            NSLog(@"Photo Not Available, fetch");
            [self.thumbnailImageView sd_setImageWithURL:[NSURL URLWithString:thumbnailURLString] placeholderImage:nil options:SDWebImageRefreshCached completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType, NSURL *imageURL) {
                if(image != nil) { NSLog(@"Lo Res Image Loaded by %ld from '%@'", (long)cacheType, imageURL);
                    self.thumbnailImageView.image = image;

                } else {
                    self.thumbnailImageView.image = nil;

                } }];

        } }];

尝试 3:

[[SDWebImageDownloader sharedDownloader] downloadImageWithURL:[NSURL URLWithString:thumbnailURLString] options:SDWebImageDownloaderUseNSURLCache progress:nil completed:^(UIImage *image, NSData *data, NSError *error, BOOL finished) {


        }];

尝试 4:

SDWebImageManager *manager = [SDWebImageManager sharedManager];

        [manager loadImageWithURL:[NSURL URLWithString:thumbnailURLString] options:SDWebImageDelayPlaceholder progress:^(NSInteger receivedSize, NSInteger expectedSize, NSURL * _Nullable targetURL) {
        } completed:^(UIImage * _Nullable image, NSData * _Nullable data, NSError * _Nullable error, SDImageCacheType cacheType, BOOL finished, NSURL * _Nullable imageURL) {

        }];

尝试 5:

SDWebImageDownloader *manager = [SDWebImageManager sharedManager].imageDownloader;
        [manager setValue:@"application/vnd.learning.events.v1+json" forHTTPHeaderField:@"Accept"];
        [manager setValue:@"en-US" forHTTPHeaderField:@"Accept-Language"];
        [manager setValue:@"application/json; charset=utf-8" forHTTPHeaderField:@"Content-Type"];
        //[manager setValue:savedEmail forHTTPHeaderField:@"Email"];
        [manager setValue:savedToken forHTTPHeaderField:@"Authorization"];
        [manager downloadImageWithURL:[NSURL URLWithString:thumbnailURLString] options:SDWebImageDownloaderHighPriority progress:^(NSInteger receivedSize, NSInteger expectedSize, NSURL * _Nullable targetURL) {
        } completed:^(UIImage * _Nullable image, NSData * _Nullable data, NSError * _Nullable error, BOOL finished) {
            self.thumbnailImageView.image = image;
        }];

在上述所有情况下，都会出现以下错误:

Error Domain=NSURLErrorDomain Code=-999 "cancelled" UserInfo={NSErrorFailingURLStringKey=https://thisisnotcorrecturl.net/api/BAImage?ActionFlagId=97&id=615, NSErrorFailingURLKey=https://thisisnotcorrecturl.net/api/BAImage?ActionFlagId=97&id=615, _NSURLErrorRelatedURLSessionTaskErrorKey=( "LocalDataTask <92586538-B07D-46FB-8694-3B29AA3F0CB4>.<7>" ), _NSURLErrorFailingURLSessionTaskErrorKey=LocalDataTask <92586538-B07D-46FB-8694-3B29AA3F0CB4>.<7>, NSLocalizedDescription=cancelled}

之前我们使用的是v3.5.4版本，可以通过以下代码下载图片。效果很好。

[self.thumbnailImageView setImageWithURL:[NSURL URLWithString:thumbnailURLString]
                            placeholderImage:nil
                                   completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType) {
                                       if (image != nil){
                                           self.thumbnailImageView.image = [self imageResizingToAspetRatio:image];

                                       }
                                   }];

如果有任何错误或建议，请告诉我。

更新 1:尝试使用 postman 下载图像。请检查图像。在我升级到 SDWebImage v4.4.5 后，相同的图像 URL 在 SDWebImage v3.5.4 上工作，它没有提供图像。

我是否缺少任何配置？还安装了 pod 'SDWebImage/WebP'，在build设置 -> 预处理器宏中添加了 SD_WEBP=1。

Error: Error Domain=SDWebImageErrorDomain Code=0 "Downloaded image has 0 pixels" UserInfo={NSLocalizedDescription=Downloaded image has 0 pixels}

http://testingurl.net/api/Image?ActionFlagId=20&id=864

授权:邮箱:kkk1@ler.com，通证:A-BE3D-WER3-847F-ER6YG5678G

Answer 1

基本上，如果 URL 包含图像，SDWebImage 从任何 URL 下载它们都没有问题。

但在您的情况下，您已尝试从 JSON 获取图像。您的服务器 API 返回一个 JSON 对象，其中包含作为 base64String 的图像。当您获得 JSON 响应时，您需要从 json 中获取 base64String，然后从 base64String 创建图像。

您可以使用此方法通过 Objective C 将字符串解码为图像。

- (UIImage *)decodeBase64ToImage:(NSString *)strEncodeData {
  NSData *data = [[NSData alloc]initWithBase64EncodedString:strEncodeData options:NSDataBase64DecodingIgnoreUnknownCharacters];
  return [UIImage imageWithData:data];
}